1. Field of Invention
The present invention relates to a one-piece molded seating shell for use in the construction of a chair, and wherein the chair has a back support portion and a seating portion interconnected by a narrow intermediate joint formed integral therewith to provide for the back portion to flex rearwardly and in torsion. More specifically, the shell is formed from composite polymeric materials reinforced with fibers.
2. Description of Prior Art
It is known to provide a one-piece molded seating shell of which the back portion can flex rearwardly. For example, reference is made to Canadian Patent 1,217,705 which refers to such a structure. The present invention relates to an improved shell of the type as described in that patent, and which gives better flexing and torsion properties without the use of any mechanical device and with a unique functional design.
In Canadian Patent No. 928,628, there is disclosed a support frame which permits a shell to be non-rigidly mounted so as to be subject to flexural and torsional stresses and strains during use. With the invention disclosed herein, there is no need to mount the shell on flexible bushings to achieve torsional displacement of the back rest. This is achieved by the shell structure and therefore the shell does not require any external back support.
According to the above features, from a broad aspect, the present invention provides a one-piece molded seating shell for use in the construction of a chair. The shell is molded from composite polymeric materials and comprises a seating portion and a back support portion interconnected therewith by a single, central, narrow intermediate integrally formed joint. At least the joint has reinforcing fibers extending therein and permitting the back support portion to flex rearwardly and in torsion.